The Norwegian territory, roughly the size of Ireland and about 1,000km (600 miles) from the North Pole, is the only place in Western Europe with this unique facility. Longyearbyen is Svalbard's biggest settlement and has about 1,800 residents
Per Sefland, Norway's governor on the archipelago, said: "If you're able to find a job, you have the right according to the treaty to come here."
The treaty was signed by World War I victors in Paris in 1920. It gave sovereignty over Svalbard to Norway, conditional on there being no barrier to entry.
It states: "The nationals of all the high contracting parties [signatories] shall have equal liberty of access and entry for any reason or object whatever to the waters, fjords and ports of the territories."
Any signatory country can ratify the treaty at any time and those on the list include Chile, India, China, Romania, Venezuela and Afghanistan.
"We are here for work and because we don't need a visa"
Young Thai immigrant to Svalbard
The treaty stands today and the visa-free rule has been extended.
"It has been a chosen policy so far that we haven't made any difference between the treaty citizens and those from outside the treaty," Sefland said.
Thailand is not a treaty signatory, but there are about 60 Thais living in Longyearbyen, second only to Norwegians according to official figures. Most are employed as cleaners.
One young Thai woman who lives in the town, and who spoke good Norwegian, said: "We are here for work and because we don't need a visa."
Another, who has lived in Longyearbyen for many years said that Norwegian coal miners brought back Thai wives from holidays during the 1970s. Before that, Svalbard had been populated by hunters, whalers and miners from Scandinavia, North America, Europe and Russia.
Polar bears are common in the
Longyearbyen, named after John Munro Longyear, the American coal miner who founded the town in 1906, lies in a glacial valley on the edge of a fjord.
It now has a university, hospital, school and hotels, restaurants and shops.
East Europeans also live and work in Longyearbyen and the pizzeria is run by Iranian brothers. In all, there are about 25 nationalities living in the town.
Hans-Henrik Hartmann, the head of the legal unit at the Norwegian government's immigration department, said: "If an asylum seeker is refused residence in Norway he can settle in Svalbard so long as he can get there and is able to pay for himself."
In the past, immigrants who have been refused a visa for mainland Norway have moved to Longyearbyen, lived there for seven years and been awarded Norwegian citizenship.
"It's not a good idea to spread the impression that the people coming here have found their lucky life - it's too cold and too difficult to find a job"
Per Sefland, governor of Svalbard
But there are two hitches to Svalbard life - the weather, temperatures in winter can fall to -40C, and limited social services.
The governor has the right to throw people off the island if they cause trouble or cannot find work or accommodation.
Sefland said: "It's not a good idea to spread the impression that the people coming here have found their lucky life. It's too cold and too difficult to find a job," he said.